Direct measurements of thermal expansion and the volume change upon melting for graphite

Abstract Increasing the temperature produces a decrease in tire volume. After longer times the volume tends to increase again. The initial decrease is attributed to the predominance of the Gough-Joule effect over thermal expansion and the delayed increase, to creep.

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Thermophysical Characterization of Two DyethylMethylAmmonium Ionic Liquids

Proceedings ◽

10.3390/ecsoc-22-05792 ◽

2018 ◽

Vol 9 (1) ◽

pp. 29

Author(s):

◽

...

Keyword(s):

Thermal Expansion ◽

Water Content ◽

Speed Of Sound ◽

Linear Equations ◽

Vacuum Pump ◽

Direct Measurements ◽

Influence Of Water ◽

Opposite Behavior ◽

Thermophysical Characterization

Density (ρ), speed of sound (U), and the derived magnitudes of two diethylmethylammoniumionic liquids (ILs) against temperature have been studied in this work. The chosen ILs were diethylmethylammonium trifluoromethanesulfonate [C2C2C1N][OTf] and diethylmethylammonium methanesulfonate [C2C2C1N][MeSO3]. In order to analyze the influence of water content, saturated and dried samples of these ILs were studied. The ILs were dried using a vacuum pump, and the saturation level (28% and 6% in weight for [C2C2C1N][MeSO3] and [C2C2C1N][OTf], respectively) was achieved by keeping the ILs in an open bottle at ambient temperature. Direct measurements of density and speed of sound were taken with an Anton Paar DSA 5000. Linear equations were used to express the correlation of both properties with temperature, and the thermal expansion coefficient, αp, and the adiabatic bulk modulus constant, KS, have been also obtained. Additionally, results were compared with previous literature data in order to have a deeper understanding of the liquid properties and detect possible anomalous behaviors. The effect of water content is different on both properties. Thus, the density of the samples slightly increases when water is removed, whereas the opposite behavior was found with regard to the speed of sound, which decreased when the water content was completely removed.

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Dimesional Changes of Ice Ih with Time

Journal of Glaciology ◽

10.1017/s0022143000033906 ◽

1978 ◽

Vol 21 (85) ◽

pp. 703 ◽

Cited By ~ 1

Author(s):

Paul R. Camp

Keyword(s):

Volume Change ◽

Apparent Volume ◽

The Other ◽

Ice Crystal ◽

Fractional Change ◽

Steel Container ◽

Direct Measurements ◽

Different Types ◽

Crystal Volume ◽

Pure Single Crystal

Abstract Two different types of experiment were reported. Both used a pure single crystal of ice freshly grown in the laboratory at 2 mm per hour. Direct volumetric measurements were made by submerging an ice crystal (volume 143 cm3) in mercury in a sealed steel container and electronically monitoring the height of the mercury in a manometer tube connected to it. Measurements over a 60 d period at —4.0°C showed a small gradual decrease in apparent volume. This could be due to the adsorption of perhaps 10-2 cm3 of air trapped by the mercury at the surface of the ice. The total un-certainties of the experiment are such that we believe we would have observed a volume dilation of as little as 2.5 × 10-6 per day. Direct measurements were also made of the change in length of ice samples from the same crystal. One was cut with length parallel to c and the other perpendicular to c. Over a 28 d period, the fractional change in length at —13.7°C was less than 2 × 10-7 per day and less than 7 × 10-8 per day ║c, leading to an upper bound on volume change of 7 × 10-7 per day. We conclude that if dilation of ice occurs with time, it is less than 10-6 per day and therefore probably not a factor which needs consideration in ordinary experiments.

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Thermal Expansion of the Workpiece in Turning

Journal of Engineering for Industry ◽

10.1115/1.2803532 ◽

1995 ◽

Vol 117 (4) ◽

pp. 542-550 ◽

Cited By ~ 23

Author(s):

D. A. Stephenson ◽

M. R. Barone ◽

G. F. Dargush

Keyword(s):

Thermal Expansion ◽

Heat Input ◽

Hard Turning ◽

Large Diameter ◽

Heat Sources ◽

Workpiece Material ◽

Form Errors ◽

Direct Measurements ◽

Cutting Zone ◽

Machining Operations

Thermal expansion of the part can be a significant source of dimensional and form errors in precision machining operations. This paper describes a method for calculating the thermal expansion of an axisymmetric workpiece. The analysis is based on a commercially available boundary element code modified to properly represent concentrated moving heat sources such as those produced in machining. The inputs required are the amount of heat entering the part from the cutting zone and the thermal properties of the workpiece material. Calculations are compared with direct measurements of expansion from tests on large diameter 2024 aluminum sleeves. The agreement between calculated and measured values is generally reasonable, although calculated expansions are consistently smaller than measured expansions. This error is probably due to errors in estimating the heat input to the part, and particularly the neglect of flank friction in heat input calculations. Sample calculations for hard turning of a wheel spindle show that expansions can approach tolerances on critical surfaces. Based on sample calculations, thermal expansion is likely to be significant when hard turning parts with tolerances on the order of 0.01 mm. For these applications, critical surfaces should be machined first, before cuts on other sections heat the part, and gaging should be carried out only after the part has cooled.

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On the thermal consolidation of Boom clay

Canadian Geotechnical Journal ◽

10.1139/t99-105 ◽

2000 ◽

Vol 37 (2) ◽

pp. 343-354 ◽

Cited By ~ 171

Author(s):

Pierre Delage ◽

Nabil Sultan ◽

Yu Jun Cui

Keyword(s):

Thermal Expansion ◽

Waste Disposal ◽

Volume Change ◽

Free Water ◽

Radioactive Waste Disposal ◽

Slow Heating ◽

Intrinsic Permeability ◽

Fast Heating ◽

Boom Clay ◽

Thermal Consolidation

When a mass of saturated clay is heated, as in the case of host soils surrounding nuclear waste disposal at great depth, the thermal expansion of the constituents generates excess pore pressures. The mass of clay is submitted to gradients of pore pressure and temperature, hydraulic and thermal flows, and changes in its mechanical properties. In this work, some of these aspects were experimentally studied in the case of Boom clay to help predict the response of the soil, in relation to investigations in the Belgian underground laboratory at Mol. Results of slow-heating tests with careful volume change measurements showed that a reasonable prediction of the thermal expansion of the clay-water system was obtained by using the thermal properties of free water. Despite the density of Boom clay, no significant effect of water adsorption was observed. The thermal consolidation of Boom clay was studied through fast-heating tests. A simple analysis shows that the hydraulic and thermal transfers are uncoupled. Experimental results from fast-heating tests showed that the consolidation coefficient does not change significantly with increased temperature, due to the opposite effect of increasing permeability and decreasing porosity. The changes of permeability with temperature were investigated by running constant head measurements at various temperatures. An indirect analysis, based on estimation of the coefficient of volume change mv, showed that the indirect method of estimating the permeability from consolidation tests should be considered carefully. Intrinsic permeability values were derived by considering the change of the viscosity of free water with temperature. A unique relationship between the intrinsic permeability and the porosity was observed, with no dependence on temperature, confirming that the flow involved in the permeability test only concerns free water.Key words: clays, thermal consolidation, adsorbed water, permeability, temperature effects, radioactive waste disposal.

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Thermal expansion of corium prepared from UO2 and Zircaloy-2

MRS Proceedings ◽

10.1557/opl.2012.1004 ◽

2012 ◽

Vol 1444 ◽

Cited By ~ 1

Author(s):

Shun Hirooka ◽

Masatoshi Akashi ◽

Teppei Uchida ◽

Kyoichi Morimoto ◽

Masato Kato

Keyword(s):

Thermal Expansion ◽

Phase Transformation ◽

Volume Change ◽

Thermal Vibration ◽

X Ray Diffraction ◽

Volume Changes ◽

X Ray ◽

Content Ratio ◽

Diffraction Patterns ◽

Ar Gas

ABSTRACTIn this study, sintered pellets were prepared from Zircaloy-2 oxide and UO2 as a parameter of content ratio (Zr contents were 0, 24.3, 49.0, 73.4, and 97.9 at% in metal). The sintered pellets were heated in 5%H2/Ar gas. UO2 pellets underwent simple thermal expansion caused by thermal vibration while Zircaloy-2 oxide pellets underwent thermal expansion and volume change with phase transformation. Finally, the 24.3, 49.0, and 73.5 at%Zr-UO2 pellet specimens showed both phenomena. However, phase transformation temperatures were lower than that of Zircaloy-2 oxide, and volume changes were much smaller. X-ray diffraction patterns obtained after thermal expansion measurements showed that the 24.3 at%Zr-UO2 specimen contained tetragonal and cubic (Zr, U)O2 while the 73.5 at%Zr-UO2 specimen contained mainly monoclinic ZrO2.

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Volume Changes on Mixing. I. Alcohol + Benzene Solutions

Australian Journal of Chemistry ◽

10.1071/ch9620001 ◽

1962 ◽

Vol 15 (1) ◽

pp. 1 ◽

Cited By ~ 32

Author(s):

I Brown ◽

F Smith

Keyword(s):

Molecular Weight ◽

Volume Change ◽

Tertiary Alcohol ◽

Volume Changes ◽

Normal Alcohol ◽

Direct Measurements ◽

Alcohol Benzene

Direct measurements have been made at 25, 35, and 45 �C of the volume changes on mixing of benzene with each of the following alcohols : methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-hexanol, and 1-octanol. These systems have positive values of VM, the volume change on mixing per mole of mixture, with maxima at mole fractions of alcohol from 0.15 to 0.35 for the normal alcohol systems and from 0.34 to 0.54 for the secondary and tertiary alcohol systems. The systems containing the three lower normal alcohols also show at 25 �C small negative values of VM with minima at mole fractions of from 0.85 to 0.98. Values of VM increase with the molecular weight of the alcohol and with an increase in temperature. For a given alcohol molecular weight the values of VM increase with alcohol type in the order primary, iso, secondary, tertiary.

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